Aqueous ink for inkjet

Abstract

An aqueous ink for an inkjet, comprising a pigment, a polymer compound that coats the pigment, a water-soluble organic solvent, and water, wherein the polymer compound has a β-diketone group and a cationic salt-forming group, and also includes a cross-linked structure based on a siloxane linkage.

What is claimed is: 
     
       1. An aqueous ink for an inkjet, comprising:
 a pigment; 
 a polymer compound that coats the pigment, the polymer compound being a copolymer obtained by reacting monomers comprising
 (a) a monomer comprising a β-diketone group and which is present in an amount of from 10 to 30% by weight of total weight of the monomers, 
 (b) a monomer comprising a tertiary amino group or a quaternary ammonium group and which is present in an amount of from 5 to 10% by weight of total weight of the monomers, and 
 (c) a monomer comprising an alkoxysilyl group and which is present in an amount of from 3 to 5% by weight of total weight of the monomers; 
 
 a water-soluble organic solvent; and 
 water. 
 
     
     
       2. The aqueous ink for an inkjet according to  claim 1 , wherein the water-soluble organic solvent is a lower alkyl ether of a polyhydric alcohol. 
     
     
       3. A printed item, printed using the aqueous ink for an inkjet according to  claim 1 . 
     
     
       4. The aqueous ink for an inkjet according to  claim 1 , wherein the pigment coated with the polymer compound has an average particle size of at least 50 nm. 
     
     
       5. A colorant, comprising;
 a pigment coated with a polymer compound that comprises a β-diketone group, a cationic salt-forming group, and an alkoxysilyl group, the polymer compound being a copolymer obtained by reacting monomers comprising
 (a) a monomer comprising a β-diketone group and which is present in an amount of from 10 to 30% by weight of total weight of the monomers, 
 (b) a monomer comprising a tertiary amino group or a quaternary ammonium group and which is present in an amount of from 5 to 10% by weight of total weight of the monomers, and 
 (c) a monomer comprising an alkoxysilyl group and which is present in an amount of from 3 to 5% by weight of total weight of the monomers. 
 
 
     
     
       6. The colorant according to  claim 5 , wherein the pigment coated with the polymer compound has an average particle size of at least 50 nm.